Miriam, do you do FISH on bone marrow trephine biopsies, that have to be decalcified before cutting and staining? If decalcifing is performed with acid like formic acid or even hydrochloric acid, DNA is degraded to smaller fragments. Successfull hybridization of this fragments is kind of chance, because it could easily happen that the wanted DNA-sequence is destroyed. If the DNA-sequence is destroyed, there is no way to restore it. Decalcifing should be performed with EDTA for a good preservation of DNA.
I have performed CISH on formic acid - decalcified bone marrow trephines with success. But we demonstrated mRNA of light chains, that are usually found in a big amount in the cytoplasm. So degrading a part of the mRNA would not influence the final result. Our protocol for BMTB is one day fixation in NBF, next day decal with 5-10% formic acid with 5-10% formaldehyde for 8 hours, then processing like the other routine specimens. Hope this helps Gudrun Lang Histolab, AKH Linz, Austria -----Ursprüngliche Nachricht----- Von: [email protected] [mailto:[email protected]] Im Auftrag von [email protected] Gesendet: Sonntag, 01. November 2009 10:50 An: [email protected] Betreff: [Histonet] FISH on B.M. Helo all, We do FISH assay on FFPE tissue with "spot light tissue pretreatment" of invitrogen. It do works on most of the tissues, but not on Bone Marrow tissue. Do you have any idea? Thanks Dr. Miriam Birnbaum Pathology Asaf Hrofeh Medical Center Israel _______________________________________________ Histonet mailing list [email protected] http://lists.utsouthwestern.edu/mailman/listinfo/histonet _______________________________________________ Histonet mailing list [email protected] http://lists.utsouthwestern.edu/mailman/listinfo/histonet
